Accurate dot placement of ink droplets on a print media with an ink-jet printer influences the quality of images printed on the print media. One problem that affects accurate dot placement is swath height errors of the inkjet printhead. Swath height errors are commonly produced by mechanical defects in the substrate of the printhead and can produce erroneous dot placement artifacts in the media scan axis.
To solve this problem, a variety of methods have been used to compensate for artifacts in the media scan axis. For example, one method included adjusting the media advance to match the swath height error of the particular printhead. With this approach, the selection of a single media advance correction scheme is applied to all printheads in the system.
However, this can be problematic in multi-printhead systems that have printheads with varying swath height errors. For example, in a particular printing system with multiple printheads, a first printhead may have a negative swath height error of 21 um, while a second printhead may have a positive swath height error of 15 um, and a third printhead may have no error at all. In this case, the single advance correction scheme will not correct the swath height errors for the entire printing system, but only one of the printheads.
In addition, a single advance correction may change the scaling factor of the image, which could have negative implications for line art drawing applications, such as printouts for computer aided design applications.
The present invention includes as one embodiment an inkjet printing method for decreasing dot placement artifacts of an inkjet printhead having at least two substrates, each with overlapping and non-overlapping nozzle rows, the method including selectively disabling at least one ink ejection element associated with at least one nozzle in the overlapping nozzle rows between substrates based on a swath height error of the substrates.